albert said: Four new metatags: generaltagcount, artisttagcount, copyrighttagcount, and charactertagcount.
Fantastic!
Edit: okay I just tried touhou charactertagcount:0 and it didn't work, unless there really are no touhou images whatsoever without a character tag, which would be impressive. But even so it brought up almost everything, so something is off.
touhou charactertagcount:1 and touhou charactertagcount:>1 seemed to bring up the right results, but only partially so. Only 3-4 pages for the first and only 5 images when doing it with idolmaster charactertagcount:1.
I guess it's still being deployed throughout the database or something? Maybe it hasn't registered the number in older images yet.
Also, shorter aliases for these might be good, if possible. Maybe something like numchar: numgeneral: numcopy: numart:, or charcount: copycount: [etc]
Updated